A passenger conveyor typically includes a series of passenger platforms which are driven in an endless path between horizontally spaced landings. The most common types of passenger conveyors are escalators and horizontal walkways. Of course, with escalators, the passenger platforms are steps, and the steps are driven in an endless path between lower and upper landings.
In addition to the actual passenger conveying mechanisms, as generally described above, most passenger conveyors include balustrades along opposite sides of the moving passenger platforms, supported by a main body frame of the conveyor, and supporting a pair of handrails movable along and guided by the balustrade constructions.
Passenger conveyors usually include two drive systems operating in synchronism, one drive system for moving the passenger platforms and another drive system for moving the handrails. Handrails drive systems may incorporate wheels, rollers, pulleys, belts and the like, all of which are movable rotationally for moving a linearly movable handrail. Often, a wheel, such as a pulley, will be used to frictionally engage and impart movement to the handrail. A drive belt also might be used, wrapped about a multiple pulley system, including an idler pulley, enabling increased belt wrap and drive capacity, and engaging and imparting linear movement to the handrail. For instance, a handrail may be sandwiched between the outer periphery of an idler pulley and a tensioned drive belt member.
One of the problems with such handrail drive mechanisms as described above, is the continuous wear on the handrail and drive member as it moves through the various pulleys, rollers, and the like. As is commonly known, a handrail is fabricated of flexible material, such as a rubbery material, plastic or the like. When the two distinct but adjacent members move through the various rotating components of the drive system, alternating back and forth bending cause a degree of relative motion between the two members which results in slippage between the handrail and the drive member which engages the handrail. This slippage causes wear of the handrail and drive belt member, not very much different from the wear encountered in tires of an ordinary automobile. Since handrails are an expensive, though replaceable, component of a passenger conveyor system, excessive wear and replacement of handrails is an expensive and time consuming proposition.
This invention is directed to solving the above problems by eliminating slippage between the handrails and their driving components, particularly in a multiple pulley-type handrail drive mechanism.